JPH0361238A - Automatic document transfer apparatus - Google Patents

Abstract

PURPOSE:To shorten the time of document transfer by providing such an arrangement that the feed operation of succeeding document sheet is started on a first exposure operation for a preceding document sheet. CONSTITUTION:A plurality of sheets of document are successively transferred into an image exposure section 101 where one of sheets of document is stopped for being exposure-scanned by moving an optical system, and the document sheet is then transferred to a document discharge bed 14 after exposure. In this arrangement, sheet feed operation for the succeeding document sheet is started before completion of exposure operation for the preceding document sheet, and is stopped once a predetermined position just before the image exposure section 101. Further, the feed operation of the succeeding document sheet is started on a first exposure operation of the preceding document sheet, thereby it is possible to increase the transfer speed of the document sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an automatic document feeder in a recording apparatus such as an electrophotographic copying machine.

[Background of the invention]

An automatic document feeder is generally used by being mounted on a document table glass (platen glass) of an image exposure unit of a copying machine or the like.

In an optical system moving type copying machine equipped with this automatic document feeder, sheet-like originals (hereinafter simply referred to as originals) are
The originals are fed out one by one by the automatic N document transport device from the original document placing table (stack section) that has been placed in the original position, and are fed onto the document table glass by the conveyor belt, where they are exposed to light by the exposure section lamp inside the copying machine main body. After that, the document is further conveyed onto the document discharge table.

Conventionally, the operation of exchanging originals on the original platen glass by an automatic document feeder is such that after a paper ejection sensor detects that the double document on the original platen has been ejected, the next original is sent out from the stack section and placed on the original platen. It was conveyed onto glass and stopped at a predetermined position. As a result, it takes a long time to exchange originals, and therefore a lot of time is required for copy processing, resulting in a decrease in copy productivity.

[Problem to be solved by the invention]

When using an automatic document feeder to automatically feed and eject documents onto the document table, copy productivity can be increased by 10% if the document is exchanged within the return time of the scanning optical system.
It becomes 0% and no time is wasted.

To achieve this, it is necessary to increase the document transport speed from the document double-feed prevention position in the stack unit to the document stop position on the document table glass surface.

Unfortunately, however, increasing the document conveyance speed causes various problems such as an increase in the size of the motor, an increase in power consumption, an increase in dust that breaks the document, and a decrease in document separation performance.

[Means to solve the problem]

The object of the present invention is to solve the above-mentioned problems in an automatic document feeder and to increase the number of copies processed.

The automatic document feeder of the present invention that achieves the above object sequentially transports a plurality of sheet-shaped YK documents to an image exposure section, stops the document at the image exposure section, and moves the optical system to scan the document. In an automatic document feeder that performs exposure and transports the document to the document eject table after exposure, feeding of the subsequent sheet document is started before the exposure operation of the preceding sheet document l1i (document is completed).
The document feeding device is configured to temporarily stop and wait at a predetermined position in front of the image exposure section, wherein the feeding operation of the subsequent document is started during the first exposure operation of the preceding document. That is.

Also, the automatic document feeder of the present invention is characterized in that the feeding operation of a subsequent document is started based on an image exposure signal from an image forming apparatus body including the image exposure section. Furthermore, this automatic document feeder restarts document feed from the temporary stop position and transports the document to the image exposure section based on a preceding document passage detection signal from a means for detecting passage of the fed document. It is characterized by:

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows the constituent countries of the document transport path of the automatic document feeder according to the present invention, and FIG. 2 shows the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document conveying system and drive system inside the apparatus, and FIG. 4 is a plan view of the main parts of the automatic document conveying apparatus. Furthermore, FIG. 5 is an external perspective view of the upper part of the copying machine equipped with an automatic document feeder. Figure 6 (
A) is a schematic diagram showing a document conveyance path. Note that these illustrated devices are automatic document feeders with an automatic document reversing function (
RADF).

First, the structure and operation of the automatic document feeder will be explained with reference to if diagrams, FIGS. 3, 5, and 6(A).

A document placement table 1 is provided on the left side of the upper surface of the automatic document feeder, and allows documents to be stacked on top of each other.

A document leading edge stopper ID is provided below the leading edge of the document mounting table 1 and is movable by the document setting tray maid SDI and the remoid SDI. A stack of originals is placed on the document mounting table 1 in a state where the leading edge protrudes near the original stack, and the leading edge of the bundle of originals is abutted against the document leading edge stopper ID to align the sheets.

When a stack of originals is placed on the original placing table #t, the presence or absence of the original on the original placing table is checked by the yK original setting detection sensor original 0
It is detected by PS2 (sheet detection sensor), and the ADF mode is displayed on the control panel 110 of the copying machine main body lOO.

Width regulating plates IA, IA are provided on the document mounting table l to regulate the width direction of the document. This width regulating plate IA is disposed on the lower surface of the document table L, and is connected to rack gears 1c and Ic that can alternately slide sideways across a binion gear IB, so that it can be moved symmetrically around the center. There is. The rank gears 1c and 1G are connected to width regulating plates IA and IA, respectively, and the amount of movement thereof is detected by a document size detection sensor PSl, so that the width size of the document can be read. Based on this read value, the standard size W and paper length are automatically converted. Therefore, by placing a stack of originals on the original placing table L and sliding the width regulating plates IA and IA so that they come into contact with the width of the originals, the various original sizes, that is, the lengths of each original, can be stored. It has become.

A pickup roller 2 is located above and near the tip of the document table L, and is movable up and down by the operation of a paper feed solenoid (latch type) SD2 and spring pressure, and is also rotatable by the driving force of a drive motor M. ing. By operating the copy button Ut of the control knob 110, the automatic document feeder is activated, the paper feed solenoid SD2 is energized and activated, and the pi-squazzo roller 2 connected thereto is lowered to feed the original. It comes into pressure contact with the top surface of the bundle, and at the same time begins to rotate by the driving force of the drive motor M, and the document is sent out.

On the document feeding downstream side of the pickup roller 2, there is provided a paper separation means consisting of a feed belt 3 that rotates around a feed roller 3A, and a double feed prevention roller 4 located below the feed belt 3. The separating paper feeding means receives the driving force of the drive motor M via the magnetic clutch N and the magnetic clutch 2, and selects the uppermost r! Separate only the original sheets and send them out.

On the document feeding downstream side of the separation sheet feeding means, a document passage detection sensor PS3, an intermediate conveyance roller 5, and a curved guide plate 6 are provided.
is the provision.

The passage of the leading edge of the original sheet sent out by the separation feeding means is detected by the original passage detection sensor PS3, and is then fed by a pair of intermediate conveyance rollers 5 in the vicinity, passing between the guide plates 6. will be delivered. When the leading edge of the document passes the document passage synchronization sensor (inverted a document passage detection sensor) PS5 disposed in the middle of this feeding path, a detection signal is generated to control document conveyance. The document passage synchronization sensor PS5 is connected to a yK document stopper 102, which will be described later. 2. Drive motor M and paper feed clutch. The operation of the transport latch K1 etc. is controlled via a timer.

Next, the rotating conveyor belt 8 and the copying machine main body 100
The original image on the top surface is conveyed while being pinched between the exposure original platen glass (hereinafter referred to as the original platen glass) 101, and is moved to fJ by the operation of the document stopper solenoid (inch type) SD3.
The document stops at the position where the leading edge of the document abuts the document stopper 102 which is protruding from the upper surface of the left end of the K document table glass lot.

The conveyor belt 8 is stretched between a conveyor belt drive roller 9, a driven roller 10.3m W, an upper presser roller 11, and a tension roller 12.

The original is exposed to light by an exposure lamp 103 inside the copying machine main body at a stop position on the original glass platen, and the lens,
An original image is formed on a recording medium by scanning with an optical system consisting of a mirror or the like.

When a series of copying processes for the original document are completed, the abutting portion of the original stopper 102 touches the yK document table glass 10.
1. The document is retracted from the top surface to release the leading edge of the document, and the document is conveyed out by the conveyor belt 8 which starts rotating again and the pair of paper ejection rollers 13.
The document is detected in step S4 and is then discharged and placed on the paper discharge tray (original paper discharge table) 14.

Furthermore, this automatic document feeder is provided with a document reversing section 30 for reversing the front and back of the document using the document reversing path. The W, stacking and reversing unit 30 includes transport roller groups 31, 32 .
33, a guide plate 34, and an inverted original passage detection sensor PS5 for detecting an original passing through the inversion section 30.

Next, the power drive system for the roller group and belt will be explained with reference to FIGS. 2, 3, and 4.

The drive motor M is a servo motor that integrates a DC motor and a speed control device (encoder, tacho generator, etc.). A toothed pulley pt that is integral with the drive shaft 20 of the servo motor M, and a toothed pulley P2 fixed to the intermediate @21.
A toothed belt Bl is stretched between each pulley, and the intermediate shaft 21 is rotated by the drive rotation of the motor M.

On the intermediate shaft 21, in addition to the toothed pulley P2, a toothed pulley P3. 1 is pivotally attached to P4 and the electromagnetic clutch. Between the toothed pulley P3 and the toothed pulley P5 fixed to the shaft end of the FX moving roller 9, a toothed belt B2 is wound and meshed to be rotatable. ing.

The conveyor belt 8 is rotated by the rotation of the conveyor belt drive roller 9.
The driven roller 10 rotates via the driven roller 10, and the toothed pulley PIO fixed to the shaft end of the driven roller 10 meshes with the toothed pulley pH via the toothed belt B5, causing the paper discharge roller 13 to rotate.

In addition, the toothed bell 1-R3, which is wound around the outer periphery of the toothed pulley P4 provided at the intermediate @1121 and meshes with the toothed bell 1-R3, connects the feed roller 3A to the gear G1. Intermediate conveyance roller shaft 2 is attached to the shaft end of feed roller shaft 22 rotated via G2; I; is integral with toothed pulley P6 and intermediate conveyance roller 5
It is wound around and meshed with each outer circumferential tooth portion of a toothed pulley P7 which is pivotally attached to the shaft end of No. 3. In addition, R1 and R2 are the above-mentioned toothed bells)
This is a tension roller that circumscribes the outer peripheral surface of R3 and creates a tension stage.

Due to the rotation of the toothed belt B3, the feed roller @22, which is integrated with the toothed pulley P6, is rotated by the gear G1. The feed roller 3A is rotated via G2, thereby the driven roller 3
Rotate the feed belt 3 wound between P8.B and the toothed pulley P8.B. With P9 and toothed belt B4,
Rotate the pickup roller 2. On the other hand, an electromagnetic clutch 2 is attached to the other end of the feed roller shaft 22, which is controlled based on an input signal to rotate the feed bell l-3 and the pickup roller 2 to feed the original.

When copying double-sided originals, the transport belt drive roller 9 starts rotating counterclockwise in synchronization with the completion of exposure of the original whose first side has been exposed in the process described above, so that the transport belt 8
The document is conveyed rightward on the document table glass 101 by the document table glass 101 .

The right end portion of the transported document is sent to the document reversing section 30. Therefore, the document tray is conveyed around the document reversing section 30 along the guide plate 34 while being sequentially nipped by the conveyance rollers 31, 32, 33, and then the right end of the document tray, that is, the leading edge in this case, is placed on the document tray. Before the document is sent onto the lath 101, the rotation of the conveyor belt drive roller 9 is switched clockwise again based on a signal from the WL document passage detection sensor PS5, in which the leading edge of the document is reversed.

The above is a schematic configuration of a drive system to which power is transmitted by the drive motor M. Next, the operation of the drive system will be explained. Figures 6 (B) and (C) are schematic diagrams showing the document feeding and conveyance process, Figure 7 is a diagram showing the rotational speed of each paper feed roller by the drive system, and Figure 8 is a block diagram of the drive system. 9 are time charts.

(2) When a stack of originals is stacked on the original tl table l and hits against the original leading edge stopper ID stopped at the raised position, the original set detection sensor PS2 detects the presence or absence of the original and the ADF mode is set.

(2) When the width regulating plates JA and IA are moved and brought into contact with the width side edges of the document bundle, the document size detection sensor PS1 detects the document width, and the CPU converts and stores the document length.

(2) When the copy button 111 is pressed, a copy start signal is input, and the copying machine main body 100 and automatic document feeder are activated.

■ This ADF activation signal applies a voltage to the document set remade SDI, and the yKf14 tip stopper ID
lower the tip of the At the same time, a voltage is applied to the paper feeding lens SD2, and the pickup roller 2 descends to press the top layer of the document bundle.

(2) At the same time, when the drive motor M starts driving, the toothed pulley Pi on the motor drive shaft 20 rotates, and the intermediate shaft 21 having the toothed pulley Pl is rotated via the toothed belt B1. At this time, electromagnetic clutches 1 and K2 are both in the ON state, and the feed roller shaft 22 is driven and rotated by the rotation of the toothed belt B3, and the gears Gl and G
2. The feed belt 3 is rotated via the feed roller 3A, and then the pickup roller 2 is rotated by the toothed belt B4.
is also rotated. At the same time, the toothed pulley P7 that meshes with the toothed belt B3 is also rotated, causing the intermediate conveyance roller 1M23 to rotate, and the intermediate conveyance roller shaft 5 to be in a rotating state.

At the same time, the toothed belt B2 wound around the intermediate shaft 21 rotates the conveyor belt drive roller 9 having the toothed pulley P5. As a result, the conveyor belt 8 wound between the a-ra 9 and the driven roller 10 is rotated. At this time, the circumferential speeds of the pickup rotor 2, feed belt 3, intermediate conveyance roller 5, and conveyance belt 8 are all set to high-speed conveyance mode v1 (for example, circumferential speed v r −1200
mm/5ec).

Due to the above-mentioned rotation of each roller and rotation of the belt, the top layer document DI of the document stack on the document table l is sent out by the pickup roller 2, and is separated by the feed belt 3 and double feed prevention roller 4, and the top layer document DI is sent out by the pickup roller 2. The first document Dl is separated and fed.

■ When the leading edge of the separated and fed original document Dl passes through the original passing detection sensor PS3, a leading edge passing signal is generated, and the timer starts timing from the generation of this signal, and the timing is reached at t3.
After counting the time, turn off the paper feed clutch 2. As a result, the leading edge of the document Di passes through the nip position of the intermediate conveyance roller 5, and then the
The driving rotation of the motor stops and becomes driven rotation.

■ The intermediate conveyance roller 5 is then rotated and the document DI
The document is fed, passes the document passage synchronization sensor PS5, and then slides on the document table glass 101 while being pinched by the rotating conveyor belt 8.

■ W of the above synchronous sensor PS5: 8 points in total from the time of passing, 1 point after t6, original f height strike solenoid SD3
When the force (g) is activated, the G strike member 102 protrudes to the upper surface of the left end of the original platen glass 101.

■ Timed from the time the original passes through the synchronization sensor PS5.
After 9 seconds, the drive motor M is temporarily stopped at 0FFt before the tip of the document strikes the original stroke <1o2r, and the motor brake is applied to make it strike the stopper due to inertia. In addition, in this embodiment, this motor OF
F is performed approximately 5 to 1Qmm in front of the strike point.

[Phase] After that, at time t8, the conveyance rig/chip Kl is turned off.
F, and the conveyor belt 8 is stopped. The clock is switched from high speed to low speed almost simultaneously.

■ At time tlO, turn on the paper feeding club, turn 2 ON and drive the drive motor M. As a result, the next document D2 is fed by the bin up roller 2 and the feed roller 3.

With the document in a stationary state in the image exposure section 1, scanning exposure by the optical system 103 on the copying machine main body 100 side is started. At this time, before or during scanning exposure, the next ff
When the leading edge of the next document D2 passes the document notification detection sensor PS3, a detection signal is emitted and a timer (or counter The document D2 is stopped at a predetermined position and kept on standby by counting the pulses (by pulse counting).

During this time, the electromagnetic clutch 2 for feeding is ON and the electromagnetic clutch Kl for transport is OFF, so the preceding original document DI being exposed is in a stopped state, but the subsequent original document D2 is in the low-speed transport mode V during this time. The leading edge of the document reaches the vicinity of the document table glass lot and is on standby. However, the operation during this time should be completed at least after the end of the scan and before the restart signal is generated.
-500mm/5ee) speed is determined.

The following document standby position described above is for various document sizes, i.e.
It is set differently depending on the length of the K document in the conveying direction.

FIG. 6(B) is a schematic diagram showing the process of feeding and conveying the preceding original DI and the succeeding original D2.

Timing by the timer starts when the leading end of the following KmD2 passes j[passage detection sensor PS3, and t2
Afterwards, the paper feed clutch 2 is turned OFF and paper feeding is stopped. Next, the driving of the drive motor M is stopped after a period of time tld from when the leading edge of the document D2 passes the document synchronization sensor PS5. In addition, the above temporary stop position P
The leading edge of the document DI located at is located near the document table glass 101 and is not in pressure contact with the conveyor belt 8, so it is close to the trailing edge of the preceding document at a short distance.

■ Next, at the end of the scanning exposure, from the copying machine main body 100
A DF start signal is issued and the exposure operation for the second original is performed. That is, by turning on the drive motor M and turning on the electromagnetic clutch Kl for conveyance, the preceding document Dl is conveyed by the conveyance belt 8, and is discharged and placed on the paper discharge tray 14 via the paper discharge roller 13. . At the same time, the subsequent document D2 slides while being held on the document table glass lot from the standby position, and reaches the document stopper 102 in the above-mentioned stopping operation, thereby completing the document exchange. At this time, the timer (8) indicates that the document is being transported in high-speed transport mode V1.

■ The timer [5°t] is activated by the above ADF start signal.
6. T? ,t8. Jin9. tlo starts at the same time.

(Mart t[3, t7 are document stopper solenoid SD3
, timers t5 and tll actuate the reset of the solenoid SD3. Further, the timer t8 issues an OFF signal for the transport latch Kl. Furthermore, timer t9. tlO and t14 are drive motor M ON;
Controls OFF.

The second document D2 is conveyed from the temporary stop position P2 to the document table glass 101 in the high speed mode V, and the timer t
After it is temporarily stopped at 9, it abuts against the document stopper 102 due to inertia and stops. Thereafter, it is operated in the same manner as the preceding document D1 to perform exposure processing and discharge.

In addition, in this embodiment, one motor and two tTfi
Although the clutches were used to control and operate the two drive systems described above, it is also possible to perform similar operations using two motors and I electromagnetic clutches.

Also, when copying double-sided originals, when the original is reversed and reversed to the IS reversing unit 30 and then transported to the original platen glass and the rear again,
The same effect can be obtained by starting time measurement from the detection of passage of the reversed original passage detection sensor PS5 and setting the temporary stopping position of the original as described above.

〔Effect of the invention〕

As described above, according to the automatic document feeder of the present invention, not only is it possible to shorten the time to feed documents, but also the low-speed separation during document feeding improves the stabilization of separation performance and smoothes document feeding. This is effective in preventing damage to the leading edge of the document. In addition, it is possible to reduce the load on the motor, save power consumption, and install a small, low-torque motor. In particular, document conveyance is controlled by starting the motor, clutch, solenoid, and various timers based on the ADF start signal from the copying machine body, and by means of detecting the passage of the preceding document.
It has the advantage that the control program is simple and clear, there are few causes of malfunction, and manufacturing costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the document conveyance path of the automatic document feeder according to the present invention, and FIG. 2 is a diagram showing the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document transport system and drive system inside the apparatus, and FIG. 4 is a plan view of the main parts of the automatic i-document transport system. Further, FIG. 5 is a perspective view of the upper part of the copying machine equipped with an automatic document feeder. Figure 6 (
A), (B). (C,) is a schematic diagram showing the document transport process, Figure 7 is a diagram showing the rotation speed of each paper feed roller by the drive system, Figure 8 is a block diagram of the drive system, and Figure 9 is a diagram showing the document feeding and transport. This is a time chart of the process. l...Document mounting table IA...Width regulation plate IB
...Binion gear 1G...Rack gear ID...
・Document leading edge stopper 2...Pickup roller 3...Feed belt 3A...Feed roller 4...Double feed prevention roller 5...Intermediate conveyance roller 6
... Guide plate 8 ... Conveyor belt 9 ...
Conveying belt drive roller 13... Paper ejection roller 14... Paper ejection tray 3
0... Document reversing section 31, 32. 33... Conveyance roller group 34... Guide plate 100...
Copy machine body lot...Image exposure section (original table glass) 1
02... Original stopper 110... Control panel Ml... Copy button K I, K 2-... Electromagnetic clutch (, MC) M...
Drive motor D...N faDI...Advance y
K draft D2...Subsequent manuscript PSl...Document size detection sensor P, S2...Document set detection sensor PS3...
Original passage detection sensor PS4... Original discharge detection sensor PS5... Reversal [Original passage detection sensor (original passage synchronization sensor)

Claims (3)

[Claims] (1) Multiple sheets of originals are sequentially conveyed to the image exposure unit, the originals are stopped at the image exposure unit, the optical system is moved to perform scanning exposure, and after exposure, the originals are transported to the original output tray. In the automatic document feeder, feeding of a subsequent sheet document is started before the exposure operation of the preceding sheet document is completed,
The document feeding device is configured to temporarily stop and wait at a predetermined position in front of the image exposure section, wherein the feeding operation of the subsequent document is started during the first exposure operation of the preceding document. Automatic document feeder. (2) The automatic document feeder according to claim 1, wherein the feeding operation of the subsequent document is started based on an image exposure signal of an image forming apparatus body including the image exposure section. (3) The next document is fed to the temporary stop position based on a preceding document passage detection signal from the means for detecting passage of the fed document.
The automatic document feeder described in .